In oligoarticular juvenile idiopathic arthritis (oligo JIA), which is the most common form of chronic inflammatory arthritis in children, synovial Tregs exhibit lower Helios and higher CTLA-4 with a Th1 skewed signature (higher CXCR3/CD161/IFNγ/Tbet), but not a Th17 skewed signature (IL-17/STAT3/RORγt/CCR6) (189). Here, STAT3 is linked to juvenile idiopathic arthritis.